The selection of straight, smooth, even-sized logs is the prime
consideration (fig. 1). Top diameters should be as uniform as possible,
but as a rule not less than 10 nor more than 12 inches. (Slightly
smaller or larger dimensions may be used if no others are available.) The
taper should be as slight as possible. For logs longer than 40 feet, the
top diameter may be less than 10 inches in order to avoid an excessive
diameter at the large or butt end.
[Illustration: Figure 1.--Starting to build the log cabin--laying the
foundation.]
Cedar, pine, fir, and larch, in the order named, are most desirable
for log construction. All knots, limbs, or bumps should be trimmed off
carefully when the log is peeled. It is best to cut the logs in late fall
or winter, for two important reasons: (1) Logs cut in spring or summer
peel easier, but crack or check to an undesirable degree while seasoning.
(2) Insect activity is dormant during the winter months; hence, if the
logs are cut and seasoned then, they are less liable to damage by insects
or rot-producing fungi.
Logs should be cut, peeled, and laid on skids well above the ground
for at least 6 months before being placed in the building. This may
not always be possible, but it is a good rule to follow. Logs should
be stored in a single deck with 2 or 3 inches between them to permit
complete exposure to the air. Logs having a sweep or curve should
be piled with the curve uppermost so that their weight will tend
to straighten them while they are drying. Where the skidding space
is limited, logs may be double-decked, using poles between tiers.
Unrestricted air circulation materially aids seasoning.
Sort the logs carefully before starting construction, using the better
ones in the front or other conspicuous walls of the building. If the logs
are not uniform in size, the larger ones should be placed at the bottom
of the walls.